American Al Qaeda may now pose the most clear and present threat to the homeland, top government sources tell ABC News.

Americans have risen high in Al Qaeda's leadership and are now helping shape strategy for attacks on the U.S.

One source told ABC that it is clear these homegrown Al Qaeda want to spill American blood.

American Al Qaeda may be even more dangerous than foreign fighters, sources say, because they know the nation's psyche and its "soft" targets, and its American recruits can often move about the country freely. In fact, during a speech to the top police chiefs in the country Monday, Homeland Security Secretary Janet Napolitano shared a stark assessment:

"The stark reality that I shared with Congress recently – and that I'm sharing with you today – is that we at the Department of Homeland Security, and I venture to say the FBI as well, are operating under the premise that individuals prepared to carry out terrorist acts are already in the country, and may carry out these acts of violence with little or no warning," Napolitano said.

So who are these self-proclaimed traitors now in the Al Qaeda leadership? The Yemeni-American cleric Anwar Al Awlaki, once a propagandist, has now gone operational, and sources say Awlaki is emerging as a top threat to America, perhaps even enemy number one after Osama Bin Laden himself. Awlaki has ties to the Fort Hood shooter, and U.S. officials say he was a key figure behind the Christmas plot to blow-up an airplane over Detroit.

While Awlaki is known to many Americans, he is now joined by a supporting cast of radicalized, and dangerous, former Americans.

Adnan Shukrijumah lived in Florida and was in the U.S. at least 15 years as a permanent resident. He is now believed to be a top Al Qaeda operational leader. The government says he helped plan a failed plot on the New York City subway system last year.

Anwar Awlaki and Shukrijumah are both believed to be actively plotting attacks right now. And sources tell ABC that Al Qaeda desperately wants another hit on the homeland before the tenth anniversary of the 9/11 attacks.

American Members of Al Qaeda Want Another Attack on U.S.

Another American Al Qaeda is Adam Gadahn, formerly of California. He's perhaps the top propagandist for Al Qaeda. Just this past weekend he used the internet to urge Muslim immigrants in the suburbs of Detroit to murder their non-Muslim neighbors.

Samir Khan lived in Queens, N.Y., and in Charlotte, N.C., but now he says, "I am proud to be a traitor to America." Sources say he is a major player behind "INSPIRE," an online Al Qaeda magazine which is aimed at radicalizing and recruiting young Muslim Americans. The magazine recently called for conducting lunch hour attacks at Washington, D.C., restaurants.

Yahya Ibrahim, a radical Egyptian cleric, allegedly penned the article that mentions this but the whole magazine is believed to be written by Khan and Awlaki.

These calls for violence fit with what senior counterterror officials have told ABC News: that American Al Qaeda are urgently pushing for its followers to launch attacks like the 2007 assault in Mumbai, India. They believe even a small scale attack, if successful, will generate international coverage and shake American confidence.

Former FBI official Brad Garrett says, "We would be just as traumatized if someone walked into a mall or train station then if you had another 9/11."

Counterterrorism officials are clearly warning Americans that the threat from the new American Al Qaeda is very real.

-- This embed didnt make it to copy for story id = 11972691.
-- This embed didnt make it to copy for story id = 11972691.
-- This embed didnt make it to copy for story id = 11972691.
-- This embed didnt make it to copy for story id = 11972691.
-- This embed didnt make it to copy for story id = 11972691.